FWIW, the max # of states is governed by how much RAM you have installed. Quick and dirty rule is about 100,000 states per GB of RAM as the default state table size on pfsense. Source: https://www.pfsense.org/hardware/ "Large State Tables - State table entries require about 1 KB of RAM each. The default state table size is calculated based on 10% of the available RAM in the firewall. For example, a firewall with 1 GB of RAM will default to 100,000 states which when full would use about 100 MB of RAM. For large environments requiring state tables with several hundred thousand connections, or millions of connections, ensure adequate RAM is available."
IMO, the state table size is probably the least of your worries when choosing hardware, since RAM is cheap. Hope this helps.